Internal heater fault. ('03 A4 Saloon)

[dazzybabie]

Hi All,
We had the first frosts of the year this morning, so i needed to get the windscreen heater on to defrost. Now heres where it got weird.
I started the car as you do, but all of the buttons on the control unit were non responsive. It was chilly in the car and the outside temp gauge shows 0.0 degrees.
The only button that would do anything at all was the rear window heater. Pressing any of the other buttons did nothing, or very little.

So i scraped away at the windscreen whilst the car was idling, and got so i could see something, and set off.
As the engine came up to temp and the heater began to blow through warm (it was set on the auto as it had been from the night before) and the car got warmer inside, the buttons came back to life, and i could adjust the temperature as i would do normally.

Anyone ever had this, or anyone able to offer any sort of explanation?

I would appreciate your thoughts as this has me boggled.

Thanks

Daz

[Alan02]

Probably nothing more than a glitch. If it doesnt do it again, nothing to worry about.

[mikeybutch]

This is odd and I would think of getting it checked rather than risking it getting worse;its vital to have them 100% in bad weather.I lost my demister flap motor for a few days last winter and really noticed it

[dazzybabie]

Everything about the heater works fine, when its warm.
Its just in the cold, the buttons dont work, but once everythings warmed up, they work fine.
Certainly not something ive come across before, and it has, as ive said, got me stumped.
Time to employ the services of an auto electrician methinks.
Daz

[mikeybutch]

Needs fixing .VAGCOM should tell you